The present Invention relates to a new and distinct cultivar of Corylus plant, botanically known as Corylus avellana, and hereinafter referred to by the name ‘McDonald’.
The new Corylus resulted from a controlled cross of female parent ‘Tonda Pacifica’ (U.S. Plant Pat. No. 22,715) and male parent ‘Santiam’ (unpatented) made in 1997. Hybrid seeds from the cross were harvested in August 1997, stratified, and seedlings grown in the greenhouse during the summer of 1998. From this cross, a total of 132 seedling trees were planted in the field in Corvallis in October, 1998. ‘McDonald’ was discovered and selected as a single plant within the progeny of the stated cross-pollination in a controlled environment in Corvallis, Oreg., USA. It was originally assigned the designation OSU 880.027, which indicates the row and tree location of the original seedling.
‘Tonda Pacifica’ (OSU 228.084) was released in 2010 (Mehlenbacher et al., 2011), is from a cross of ‘Tonda Gentile delle Langhe’×OSU 23.024 (=‘Barcelona’×‘Extra Ghiaghli’). ‘Santiam’ (Mehlenbacher et al., 2007), released in 2005, carries a dominant allele for a very high level of resistance to eastern filbert blight (EFB) from ‘Gasaway’ (unpatented). ‘Tonda Gentile delle Langhe’ (unpatented), the female parent of ‘Tonda Pacifica’, is an important cultivar in Piemonte, northern Italy. ‘Barcelona’ (unpatented), Oregon's most widely planted hazelnut cultivar, is known as ‘Castanyera’ where it originated in Catalunya, Spain. ‘Extra Ghiaghli’ (unpatented), obtained from Greece, is a clone of the important Turkish cultivar ‘Tombul’. ‘Gasaway’ (unpatented) is the source of a single dominant gene for resistance to eastern filbert blight.
The new cultivar was asexually reproduced by rooted suckers annually for nine years (2004-2005, 2007-2013) in Corvallis, Oreg. The new cultivar was also asexually propagated by whip grafting in 2005 in Corvallis, Oreg. The unique features of this new Corylus are stable and reproduced true-to-type in successive generations of asexual reproduction.